This invention relates to semiconductor materials. More particularly, it is concerned with methods of introducing conductivity type imparting material into III-V compound semiconductor materials.
Zinc is often introduced into III-V compound semiconductor materials as an acceptor material which imparts p-type conductivity to the III-V compound semiconductor material. One conventional procedure for diffusing zinc into III-V compound semiconductor materials employs a sealed ampule technique. This method, however, is cumbersome and is not suitable for large-scale production with large wafers of semiconductor material. Open-tube methods have been developed for diffusing zinc into some III-V compound semiconductor materials. In these methods a high zinc vapor pressure is obtained by dissolving zinc in a melt of a material such as tin or gallium or by coating the wafer being processed with a zinc containing oxide. In addition an over-pressure of arsenic is necessary in order to prevent loss of arsenic from the wafer which results in degradation of the wafer surface.